1. Field of the Invention
The present invention relates to surgical fixation of soft tissue to bone. More specifically, the present invention relates to apparatus and methods for securing soft tissue to bone using a suture anchor equipped with a tissue-fixation disk.
2. Description of the Related Art
When soft tissue tears away from bone, reattachment becomes necessary. Various devices, including sutures alone, screws, staples, wedges, and plugs have been used to reattach soft tissue to bone.
Recently, suture anchors have been developed for this purpose. Some suture anchors are designed to be inserted into a pre-drilled hole. Others are self-tapping and have screw threads.
U.S. Pat. No. 4,632,100 discloses a cylindrical suture anchor which includes a drill bit at a leading end for boring a hole in a bone. The drill bit at the leading end is followed by a flight of threads for securing the anchor into the hole bored in the bone by the drill bit. U.S. Pat. No. 5,370,662 discloses a self-tapping suture anchor having a flight of threads around a solid body. U.S. Pat. No. 5,156,616 discloses a similar suture anchor having an axial opening for holding a knotted piece of suture.
U.S. application Ser. No. 08/954,206, filed Oct. 20, 1997, the disclosure of which is incorporated herein by reference, discloses a corkscrew suture anchor which is designed to provide enhanced pull-out strength in cancellous bone.
The devices disclosed in the above-cited patents anchor suture to bone, but require the surgeon to tie a knot in the suture arthroscopically in order to achieve fixation of the soft tissue to the bone.
U.S. Pat. No. 5,720,765 to Thal, issued Feb. 24, 1998, discloses suture anchors with pre-attached, tissue-anchoring means. These devices lack various features of the present invention, including, for example, means for engaging the anchor and the anchoring means with a driver. In addition, Thal '765 does not disclose means for holding the suture anchor on a driver or for testing pull-out strength of the inserted anchor.
Thus, the need exists for soft tissue fixation devices that do not require arthroscopic knot tying for fixation, and which provide benefits such as advantageous means for inserting and testing the fixation devices.